Abrasive finishing machine



Oct. 1, 1957 A. J. LEWIS m 2,807,9

I ABRASIVE FINISHING MACHINE Filed June 17, 1955 e Sheets-Sheet 1 INVENTOR ARTHUR J. LEW/6,3.

BY Jam *M/ ATTORNEYS Oct. 1, 1957 A. J. LEWIS Ill ABRASIVE FINISHING MACHINE Filed June 17. 1955 6 Sheets-Sheet 2 ARTHUR LEW/5,3fd

B'Y m Wm ATTORNEYS Oct. 1, 1957 A. J. LEWIS 1n 2,807,915

ABRASIVE FINISHING MACHINE Filed June 17, 1955 6 Sheets-Sheet 5 INVENTOR AR THUR J. LEW/s, 5RD.

BY '9 WM ATTORNEYS Oct. 1, 1.957 A. J. LEWIS m 2,807,915

ABRASIVE FINISHING MACH-INE Filed June 1'7, 1955 6 Sheets-Sheet 4 INVENTOR ARTHUR J Lew/s, 3R0.

ATTORNEYS 1957 A. J. LEWIS m 2,807,915

' ABRASIVE FINISHING MACHINE Filed June 17, 1955 6 Sheets-Sheet 5 INVENTOR AR THUR J L EW/d, 5R0

ATTORNEYS 6 Sheets-Sheet 6 INVENTOR ATTORNEYS Oct. 1, 1957 A. J. LEWIS m ABRASIVE FINISHING MACHINE Filed June 17, 1955 m m NW n I md. Nm 3 ow m w R 8 R NM 7 MM. a \& hm OW MW Mum Wm Am ml V hm 0% 0% Wm QQ |l.i. h a a ma $1 A E 8K K United States Patentf) 6 2,807,915 1 ABRASIVE lFINISHIlSIG MACHHNE Arthur J. Lewis, III,- New London, N;; H., assignor to The' -A utoyreCompany, Qakville, Conn.-, a corporation of Connecticut ApplicationlJune 1,7, 1,955, S .er-ial No. .516,079-

8 Claims, (Cl'. 51-'-70) them have had numerous disadvantages, such as diflic'ulties in adjustment, high cost, and non-uniformity of finish, and is accordinglyen object of the present invention to providemechanism for overcomingthese difiiculties.

Another object of the inventionv is the provision. of means forfinishing such rods by means of abrasive tape.

Yet another object of the invention is the provision of an abrading head for a mechanism-of the above type, so constituted as to' permit the removal ofthe abrading head for repairs or reconditioning without necessitating the removalofthe' elongated Wire from the machine.

A further objectis theprovision of meansforadjusting each individual head to any desired angular position about the work pieceand for' locking the head in said position.

Yet another object of the. invention is the provision. of means for controlling the feeding .of abrasive .tapein coordination with; the movement of means f or pressing. the abradingtape. against the. wire.

A further object, of the invention! is the provision .of a. mechanism having, a plurality of separate abrading heads,

the mechanisrnbeing so constitutedthat all of the abradingv heads are interchangeable and readily removable fromthe machine Withoutthe necessity of removing and re threading the. wire.

These and other novel features and objects of the invena.

tion will. become more readily. apparentwhen considered in the lightof the following description taken in connection.

with the accompanyingdrawings, wherein one embodiment, of the invention is illustrated. It is to be expressly-under;

stood, howeven-that the: drawings are-employed for the purpose of illustration only, and are not designed as a, definition of the limitsof the invention, reference beingv had for this purpose to theappended claims.

In the drawings, wherein similar reference numerals refer to similar parts throughout theseveral views:

Fig. l is a front elevation view of the mac hine, i n ma i 93 3;

s s a r gm tary, of h -m chani m o reciprocating the abrading heads of the machine,

Fig 3 is another-view, partially in section, of the recip rocating mechanism;

Fig. 4 is a view of the crank shaft of the recipropating mechanism;

Fig. 5 is a view showingthe mounting-of theabrading heads on the reciprocating portion of the rnechanisrn and k1 mountedgon 1a shelfs29 extending outwardly. fronrthe.

n 2,807,915 Patented, O t- .1', .1957.

represents two .parts of abradingunits orientedat v (iii-, ferenhangles aboutthe axis of the wire being {treated;-;

Fig. 6 is a front elevation of oneof thegabrading headsg;

Fig. is a sectional view ,taken alongline ;-77 in Fig. it is asectionaliyiew of the abradi-nghead-ttaken l o F 6;

Fig.9 is aschematicview of the control and. actuating mechanism for the mechanism of the abrading heads;

1 Fig. 10 isa viewof a switch control mechanism for; the abrading, heads;

Fig. 11 is aside elevation of one; of thetape pressure blocks of the abrading heads, and.

Fig. 1-2 is an end view of the .pressureblockshown in, Fig.

In general, and -referring more..par.ticularly to Fig. '1,- the abrasive finishing. machine includes a body portion .4 havin'gjafrontpanel; 5rprovided' with a plurality of pegs- 6 for-holding rollsof abrasive tape, not shown, two rolls being provided for eachhead.v As willbe explained morefully'hereinafter, a pair of oppositely. reciprocatingabra,

sive head supporting plates 7 providedwith head brackets.-

7a are-.suitably. -mounted adjacent the front face of panel" 5, and are provided with a plurality of abrasive finishing heads. 8as shown in Fig; 5; A bull block mechanism 9 is mounted at the rightiend of the machine to draw the wire to be finishedthrough the machine, while a'wire -suptween ;the' oppositely reciprocating heads by frictional engagement-of thetapes therewith which-might tend to.

buckle the. wire. In the embodiment shown, each of the plates 7- is provided-with twelve abrading heads, but it willbe understood that'any desired number may be used, depending'on the type of workto be finished.

The'reciprocating mechanism forthe abraiding heads is shown in Figs. 2 to 4 inclusive,- and includes a crank shaft- 13 having a driven pulley 14 connectedto a drive motor 15 by means of a belt 16.- As shown in Fig. 4, the crank shaft 13 has opposed throws 13a and 13b positioned 180 apart. Two frames 17, one or" which is linked to the-crankshaft throw position 1311 by means of a connecting rod 18 and theother beinglinked to the throw position'13b by meansof a connecting rod 18a, accordingly havereciprocatingmotion .in opposite directions on rod-s 17a by means of bearings 17b. The rods 17a are supported on channel members extending horizontally between front panel 5 and a rear panel 5a of the machine, and preferably secured to thepanels by welding.

Referring'now to Figs. 6, 7, and 8, each abrading-head includes a circular plate 20 having a central pilot aperture 21 and a slot '22 extending'therefrom to the periphery-ofthe plate. .The abrading head includesv upper and lower tapeguides 2 andlfil having slots 25 and extending therethrough for guiding a pair of tapes in face to face.

relationship across awork piece 11 which is drawn through the .machine by the operationof. the bullblook.v As will bev apparent from the drawings,.the work piece passes through the apertures 21 in the plates 20. As shown more particularly in Fig.. 7, a pair of cylinders 28 are pivotally plate as by means of pivot pin 30. These cylinders have differential pistons a mounted therein, fluid under pressure being supplied to one side of the pistons through a conduit 31, and to the other side of the pistons through conduits 32. A pair of bell cranks 33 are pivotally mounted on the shelf in opposed relationship by means of pivot pins 34 and are connected to pistons 30a by means of pivot pins 36. A pair of pressure blocks 37, to be described more fully hereinafter, are pivotally connected to the bell cranks by means of pins 38, the arrangement being such that the pressure blocks are on opposite sides of the wire passing through the machine and are adapted to be urged against the tapes on either side of the wire to effect substantially uniform engagement of the tapes with the surface of the wire.

As heretofore stated in connection with Fig. l, pegs 6 are provided on the front of the machine panel 5, on which rolls of abrasive tape, not shown, are mounted when the machine is in operation, a pair of such tapes being led through slot 25 of upper guide 23, past the work piece 11 on opposite sides thereof, and through the slot 26 in the other tape guide 24, the used tape falling into bins, not shown, at the bottom of the machine, and being cut off below the abrading head and removed periodically by the operator. The abrasive surfaces of tapes are in face to face relationship in passing through the head, and consequently on operation of the pressure blocks by the cylinders, are pressed against the surface of the work piece to be abraded during the reciprocating movement of the heads along the workpiece.

Feed mechanism is provided for the tapes comprising a pair of rubber tired rollers 39 and 40 which are adapted and positioned to effect frictional engagement with the outer surfaces of the tapes through an opening 41 in the lower tape guide 24 opening. into the slot 26. Feed roller 39 is mounted for rotation on a shaft 42 rotatably mounted in the head, and referring to Fig. 8, a one-way clutch mechanism 43 of conventional type is mounted on the shaft with one of its relatively rotatable parts connected with the shaft, and the other part connected with the feed roller 39. A lever 44 is connected to the shaft, and the outer end of the lever is connected to a piston rod 45 of a piston 45a in feed cylinder 46 mounted on a portion of the head as shown. The lever 44 is connected to the rod by means of a link 47, the latter being pivotally connected at one end to the lever 44 and at the other end to a connector 43 threadedly mounted on the outer end of the piston rod 45. As shown in Fig. 8, the connector is provided with a slot 4-? extending from the piston rod outward, and a clamping screw serves to draw the slotted portions of the connector together to clamp it firmly against the threaded piston rod to prevent movement of the connector thereon. As will be explained later, the one-way clutch 43 is so constituted that during upward movement of the piston rod 45 as shown in Fig. 6, the r roller 39 is rotated to feed tape downward through the slot 26 of the guide 24, while on downward movement of the piston rod following the feed stroke, the shaft is rotated without effecting movement of the roller 39. The feed cylinder 46 is secured to the head by means of a nut 51, and since the construction of the cylinder is such that the travel of the piston rod is limited to a predetermined amount, adjustment of the feed stroke can be obtained by disconnection of the links 47 from the connector 4S, and then turning of the connector 48 on the threaded portion of the piston rod 45 to move it up or down to change the feed stroke. The end of the feed stroke is determined by abutment of the connector 48 with the lower face of the nut 51.

The feed roller 4 is rotatably mounted on a resilient shaft 52. secured to the head, with the roller secured against movement therealong, and the rollers are so aligned axially along the shafts as to engage the tapes substantially along their longitudinal center lines. This arrangement has been found to provide an eflicient tape CAD feed, and by feed of the tapes with the rollers engaging the tapes along their longitudinal center lines, the tapes tend to feed through the guide slots in a straight line without deviating in either direction from their centralized positions therein. In order to adjust the frictional engagement of the rollers with the tapes, the shafts 42 and 52 are mounted on movable supports 53 and 54. The supports are preferably secured to plate 20 of the head by suitable bolts 55 and the other end of the supports are provided with slots, not shown, through which cap screws 56 pass. Thus by loosening the cap screws 56, the supports 53 and 54 can be rotated in either direction to position the feed rolls correctly with respect to the center line of the tape guides, as well as to determine the degree of frictional engagement of the rollers with the tapes. The feed cylinder 46 is provided with ports 57 and 58 which serve to admit fluid under pressure to the cylinder to move the piston 45a and the piston rod 45 in the desired direction in the cylinder.

In the preferred form of the invention, the pressure block cylinders and feed cylinders are operated by compressed air controlled by solenoid valves, and a schematic arrangement for the cylinders as shown in Fig. 9. An intake manifold or compressed air reservoir 59 is provided, preferably extending along the entire length of the machine adjacent the abrading heads, and is connected by a conduit 60 to a pressure regulator valve 61 for each head which may be set to provide a compressed air output at any desired pressure, this valve being of well known and conventional construction. The valve is provided with two outlet conduits 62 and 63, the conduit 62 being connected to conduits 32 of the pressure block cylinder 28, and the conduit 63 being connected to the inlet port of a threeway solenoid valve 63a of conventional construction. This valve has an exhaust port 64 and an outlet conduit 66 connected to conduits 31 of the air cylinders 28. The valve is so constituted that when solenoid 67 is energized as will be described hereinafter, the valve is operable to establish communication between conduits 63 and 66, and to prevent communication between port 64 and conduit 66, while on deenergization of the solenoid, the valve is operable to prevent communication between conduit 63 and 66, and to establish communication between conduit 66 and the exhaust port 64 to exhaust air from the right end of the cylinders 28. A second solenoid valve 68 is provided for controlling the operation of the feed cylinder 46, being provided with inlet port 69, exhaust port 70, and outlet port 71, the latter port being connected by a conduit 72 with the port 58 in the feed cylinder. Port 57 of the feed cylinder is connected to the conduit 66 by means of a conduit 73. The operation of the solenoid valve 68 is substantially the same as that of the other solenoid valve, the valve being operative when solenoid 74 is energized to connect inlet port 69 and outlet port 71 and to prevent communication between these ports and the exhaust port 70. On de-energization of the solenoid, the valve is operative to prevent communication between ports 69 and 71, and to establish communication between ports 71 and 70. It will be noted that the inlet port 69 of the valve is connected with the conduit 60 leading to the reservoir by means of a conduit 75, and it will thus be apparent that energization of the solenoid valve 68 operates to supply reservoir pressure to the left end of cylinder 46 through the conduit 72.

The solenoids are preferably of the alternating current type adapted to be connected to a volt electric circuit, and one wire 76 of the electrical circuit is connected to a common terminal 77 of the solenoids 67 and 74. A selector switch '73 is connected in the common line 76 leading to each pair of solenoids for controlling each abrading head in order that the control valves for each head may be separately rendered ineffective at the will of the operator.

A" switch mechanism -79 is providedswhich includes spring leaves 80, 81, and 82, supported by means'of in-' sulating blocks 83 "and 84. The spring fleaves-i 80 I'and 82' areprovided"witl1"electricalcontaots 85 a nd86; while thespring le'af sl is provided with lower and upper con tactsQ87i1and-88. Thearrah'gement'of the spring leaves 92 6f nsula ting material is secured' to the outer end of the' 'sprin'gleaffl by mean" of screw 93, and is normally in engag'emeht with the earn as shownwithout opening the-{contacts 85' an'd 87, On rotation 'of the 63111,"!116 lobe eventually-strikes the' follower' 92fraising the leaf 81' to 'disengag'eeonta'cts 85 and 87; and to thereafter engage ."c'oritac'ts" 88- 86. The other wire 94 from noid 67 by a wire 95, while the upper leaf 82" is connected to the solenoid 74 by a wire'96I-It will be parent *frdm' 'theforegoin that with the' -cam vin positioit shd -th' solerioid 67' will'be energized, while on engagement: of '{the 'cam lobe with the follower 92, the

spring rear 81will' ber'aised "momentarily to sequentially disengage conta I s- 85:aud 87 "andto'engage contacts 861 mass to energize F solenoid 74-. 1 This-arrangement, to'

gather with thejc'ornpressed air operation of the cylinders,

to'be r'noire fully explained-hereinafter, insures that the pressure" blocks 37 will befull'y retractedbefore thel cylindef 46 1s operated'to feed "fresh tape" to the abrading lzone adjacent -the"wir'e.' -It will be *noted that. an additional switch 97 is shownbtit in a position' reversed from "the switch 79 this switch-being connected in the same man'- nerasthe 'switchi79i I I As"will"be"more fully explained, a pair of abradlng heads '8 are attached to each of the -brackets 7a on the reciprocating plates 7 on the abradiug machine, and each pair of switclies'such as those shown" in Fig. 9 is adapted to controlthe operation -of thepair of heads 'on'each bracket-L IThusfas-shown-inFig. 'lOQa plurality of switches 79and'97; spaced"l80='apart ab'out'shaft 90.","a'readapted tobe operat'ed byia plurality of the cams 89 which are mounted for TOfatlOIlfWlflYthC shaft 9.0"mounted on a switch control unit 98'. The latter unit includes the cams and'car'n'shaft as shown,'the shaft being'connected to a speed r'educer'99yand the reducer being driven: through pulleys 100 and 101 and a V belt 102 by means'of a suitable electric motor 103'; Thus, each 'of' the" units 98 controls all "of the abrading-heads on 'one'o'f the plates 7 on the front of themachine; and tw'o' of these units are provided in order to e'ffectcontrol of all the abradin'g heads on the'machi'ne; The lobes of'adjacent" cams on units 98 are'preferably'spaced60 apart about the shaft, so that'the'pre'ssure blocks of only two heads'oneach of theplates-7 are retractedat the same time.

The construction'of the pressure blocks '37 is shown more particularly in'Figs. l1- and 12', it being noted that these are oblong blocks provided with lateral bores 104 centrally located therein and adapted to receive the pivot pins 38 shown in Fig. 7. The surfaces of the blocks fac ing the wire are provided withresilient rubber-like facings- 105,'these'facingsbeing provided with grooves 186 contoured and adapted-topress the abrasive tapes uniformlyagainstthe surface of the wire being abraded in the machine.- In order that the pressure blocks may readily adapt themselves to thecontour of the wire being finished, the lateralbores 104are preferably made slightly larger than the pivot pins 38 which secure them to the bell cranks.

Referring now to Fig. 5, it will be noted that a fragmentary portion of one of the reciprocating plates 7 is shown having a bracket 7a mounted thereon by means of a plate 187 and suitable cap screws 108, each of the brackets being provided with diagonal braces 109, connectedi atone end to the'zbra'cketzand at the other end to tl1e-"plate;i.In additioiitto the foregoing the'bracket 7a is providedfoneither side'thereof withpilots 110 which,

arei tadaptedi to-ixengage; the: pilot. bores 21in the head plates 20,?these; pilots; blHQ' PIOVldfldi'Wllh' central aper-. tures for the? passage of wirell th'erethrough; The heads; are. secured Eto thevbracket by clamps 111', these clamps.

beingisec'ur'ed to the bracketrand urged against the head plate. ZGibyamean s:of'capwscrews1124 'Whenthe head is properly positionedwangularly aboutthis axis of the wire, the cap screws aretightened; andrthereafte'r the clamps hold .the abra'dinghe'ad zin .thechsen position. In the event; it isdesired to remove the head for repairs or the likegzthescap screws and:clamps are removed, whereupon the 'headm'ay be rotated in such a manner that theslot 22Iis. directedtoward the plateS, forming the frontportioniof .the machine,*andvwhendisengaged from the pilot;

shown: moved to the leftzoffi the pilot in order to more fully show 'the. construction: ,which permits the ready removal of the head/from:the rnachine. It will be understood-,v'of course,:that theeheadscaneeither be moved axially of the: machine and .thensrotatedvto bring the slot in the right-position to permit1removal, or can first be removednfromzzthe p'ilotxa'nd. .thenarotated to obtain the proper slot alignment. It will also be noted that; in Fig. 5, theitlefthan'd'ahead :isl shownsrotated bodily about the wire: from the positionzofthe head on the right side ofthebracket. x Thus the 'pressure=blocks of the pairof heads:oneach:bracket maygbe-so adjusted asto give a substantially 360 coveragerin the 'abrading zone adjacent to wire}: It is also pointed out that thewire tends to twist?slightlyfiuriligcits passagethrough the machine, andthe' feature which permits theangularadjustment of the,

heads aboutithezwireservexto permit proper adjustment of "the? heads to give a uniform abrading action over the is 'providedfor' controlling' 'the air pressure utilized to operate ea'chrindividual -abrading' head. This permits individualadjustnaent ofgtheforce with which the pressure blocks engage the abrasive tapes in accordance with the grit of the tapes; and also permits the heads near the right endofthe-machine to be-adjusted' to apply the pressure blocks with" a diEBICHtTfOICG'fIOm that'at which the blocks atthe leftend of the machineare applied in order to obt'aim-a better finish'on the wire. With regard to the operation of the pressure block cylinders 28, it will be noted that the-left ends of the cylinders are supplied at all times withiairpressure atthe pressure for which the corresponding regulator valve is set, and that when the, blocks are in tape engaging position, the pressure at the,

right end of'the cylinders is also that supplied by the pressure-regulator valve. Consequently, with the blocks in-applied position; thefor'ce with which the blocks are applied isa function of the difference in the two areas of the differential piston in the cylinder and the pressure suppliedby the regulator valve, and this force varies directly with the pressure at which the pressure regulator,

valve is set.

The use of pressurein the leftend of the cylinders; to;

retract the pressure blocks insures a quick retraction of the blocks which does not necessarily occur when springs are used to perform this function. In order to secure a satisfactory tape feed without dragging the tapes across the faces of the pressure blocks, it is essential that a quick release of the pressure blocks be obtained when the cam lobes operate the switches, and this is accomplished by the arrangement described. In order to insure a full release and retraction of the pressure blocks before the tape feed takes place, the switch contacts of the control switches, as heretofore indicated, are arranged to operate sequentially with a slight interval between the de-energization of the solenoid valve 63a and the energization of the solenoid valve 68. The de-energization of the solenoid valve 63a, which controls the pressure block cylinders, also acts to release the air from the upper end of feed cylinder 46. Thereafter, on subsequent energization of the solenoid valve 68, compressed air at reservoir pressure issupplied to the lower end of the cylinder in order to feed a fresh supply of tape to the abrading zone. Due to this control arrangement, the pressure blocks are definitely retracted before any tape feeding action occurs, and accordingly the tape is fed without any tendency to drag across the rubber facings of the pressure blocks which might tend to cause undue wear of the facings. Due to the positive air actuation in both directions of the pressure blocks and the feed mechanism, the time interval required for the feed cycle.

is very short, and consequently the pressure blocks remain in engagement with the tapes to urge the latter against the wire during a large portion of the time during which the machine is operated, thus resulting in a more efficient abrading action.

It will thus be apparent from the foregoing description and from the drawings, that a simple and efficient abrasive finishing machine has been provided, so constituted as to accommodate a plurality of separate abrading heads which may readily be adjusted to any angular position about the axis of the wire being abraded, and which also may readily be removed from the machine for repair or adjustment without the necessity of unthreading the wire from the machine and thereafter rethreading the wire, which is a somewhat tedious and time consuming operation, particularly with the larger sizes of Wire. in addition, all of the heads may be made interchangeable, which greatly facilitates the manufacturing operation and also reduces the cost of the machine.

Novel control mechanism has also been provided which insures a positive and rapid operation of the pressure blocks and feed mechanism, the sequence of operation being such that the pressure blocks impose no restriction on the feeding of fresh tape to the abrading zone. The solenoid valves for each head may be located directly back of the plate 5 on the front of the machine in order to avoid delay in the supplying of air to the heads and the exhausting of air therefrom, and individual pressure controls or regulator valves have been provided adjacent the solenoid valves for each, head for controlling the force with which the pressure blocks engage the abrasive tapes and urge them against the wire. In addition to the foregoing, selector switches have been provided in the circuits leading to each individual head in order that each head may be rendered inoperative by the operator if desired simply by opening ofthe desired selector switch.

The use of single feed rolls on either side of the tapes has also been found desirable, as this tends to avoid sideways movement of the tapes in the slots in the tape guides on the heads. The feed rolls may be readily adjusted to position them symmetrically with respect to the guide slots in the tape guides, and also to adjust the force with which they engage the tapes. When a pair of spaced rolls is utilized on each tape for feeding, the tendency is for one roll to be adjusted to engage the tape with more force than the other roll, a situation which results in overfeeding of one side of the tapes and underfeeding of the other side of the tape, causing the tape to bind'in the feed slots. This is entirely overcome by the present arrangement.

With a mechanism of this type, the abrasive coating of the tapes is substantially all utilized, and unused tape may be fed to the abrading zone as fast as it is used, thus resulting in a substantially uniform abrading action which is difficult to obtain by the use of abrasive belts or grinding wheels. With the mechanism of the invention, the wire is stroked longitudinally with successive unused portions of the abrasive tapes, and the tapes extend across the line of movement of the wire, thus permitting the tape to be fed from large rolls which are supported on stationary portions of the machine.

Although the invention has been illustrated and described in considerable detail, it is to be understood that the same is not limited to the form shown, but may receive a variety of expressions as will be readily apparent to those skilled in the art. Reference will, therefore, be had to the appended claims for a definition of the limits of the invention.

What is claimed is:

1. Mechanism for abrasively finishing the surface of an elongated work piece including a bracket having an aperture for the work piece, means for reciprocating the bracket along the longitudinal axis of the work piece, an abrading head including a plate having an aperture for the work piece and an open ended slot extending from said plate aperture to the outer edge of the plate, tape guide means on the plate for guiding a pair of tapes from a remote tape source across the work piece on opposite sides thereof, a pair of opposed pressure blocks adapted to engage and press said tapes against the work piece, power means for advancing and retracting the pressure blocks toward and away from the work piece, power means for feeding unused tape to the region between the pressure blocks and work piece, and means for removably mounting said abrading head on said bracket including pilot means associated with the plate and bracket for rotatably mounting the head on the bracket for bodily rotation about the work piece, and clamping means for clamping the head to said bracket in any desired position of rotation about the work piece, said pilot means being so constituted as to disengage on limited movement of said head away from the bracket lengthwise of the longitudinal axis of the work piece, whereby said head may be removed from the mechanism laterally of the work piece with the latter passing through said slot.

2. Mechanism for abrasively finishing the surface of an elongated work piece as set forth in claim 1, wherein a plurality of said brackets and said heads are mounted for rectilinear reciprocation at spaced apart intervals lengthwise of the longitudinal axis of the work piece.

3. Mechanism for abrasively finishing the surface of an elongated work piece as set forth in claim 1, wherein said pilot means includes a short hollow cylindrical member extending outwardly from said bracket axially of the work piece and a bore centrally positioned in said plate and adapted to slidably engage said pilot.

4. Mechanism for abrasively finishing the surface of an elongated work piece including a bracket having an aperture for the work piece, means for mounting the bracket for rectilinear reciprocation along the work piece, a pair of substantially identical abrading heads each including a plate having an aperture for the work piece and an open ended slot extending from the aperture to the outer edge of the plate, tape guide means on the plate for guiding a pair of tapes from a remote tape source across the work piece on opposite sides thereof, a pair of opposed pressure blocks adapted to engage and press said tapes against the work piece, power means for advancing and retracting said pressure blocks, power means for feeding unused tape to the region between the pressure blocks and work piece, and means for removably mounting said abrading heads in opposed relationship on opposite sides of said bracket including pilot means associated with said plates and bracket for rotatably mounting the heads on the bracket for bodily rotation about the work piece, and clamping means for independently clamping each head to said bracket in a desired position of rotation about the work piece, said pilot means being so constituted as to disengage on limited movement of said heads away from said bracket longitudinally of the work piece, whereby said heads may be removed from the mechanism laterally of the work piece with the latter passing through said slot.

5. Mechanism for abrasively finishing the surface of an elongated Work piece as set forth in claim 4, wherein said pilot means includes a centrally located hollow cylindrical pilot extending outward from either side of said bracket, and the plates of said abrading heads mounted on said bracket are provided with bores adapted to slidably engage said cylindrical pilots.

6. An abrading head mechanism adapted to be reciprocated along an elongated work piece including a bracket adapted to be reciprocated therealong, an aperture in said bracket for the work piece, and an abrading head on said bracket including a plate having an aperture for the work piece and an open ended slot extending from said plate aperture to the outer edge of the plate, tape guide means on the plate for guiding a pair of tapes from a remote tape source across the work piece on opposite sides thereof, a pair of opposed pressure blocks adapted to engage and press said tapes against the work piece, power means for advancing and retracting the pressure blocks, power means for feeding unused tape to the region between the pressure blocks and work piece, and means for removably mounting said abrading head on said bracket including pilot means associated with the plate and bracket for rotatably mounting the head on 10 the bracket for bodily rotation about the work piece, and clamping means for clamping the head to said bracket in a desired position of rotation about the work piece, said pilot means being so constituted as to disengage on limited movement of said head away from the bracket longitudinally of the work piece, whereby said head may be removed from the bracket laterally of the work piece with the latter passing through said slot.

7. An abrading head mechanism as set forth in claim 6, Wherein substantially identical abrading heads are mounted in opposed relationship on either side of said bracket.

8. An abrading unit for an abrading mechanism as set forth in claim 6, wherein the power means for feeding unused tape to the region between the pressure blocks and Work piece includes a pair of feed rolls for said tapes positioned to engage the tapes on their outer surfaces substantially along the longitudinal center line thereof, means for adjusting one of said feed rolls toward and away from the path of the tape engageable thereby one of said feed rolls into frictional engagement with the tape, a one-way clutch associated with the other of the feed rolls, and a fluid motor mounted on the head and connected with said one-way clutch, said fluid motor being operable to advance the tape a predetermined distance during each cycle of operation of the fluid motor.

References Cited in the file of this patent UNITED STATES PATENTS 443,795 Root Dec. 30, 1890 2,320,142 Illmer May 25, 1943 2,365,640 Illmer Dec. 19, 1944 2,728,171 ONeill Dec. 27, 1955 

